Methods and apparatus for access, enablement and control by devices in TV white space

ABSTRACT

Methods and apparatus for access, enablement and control of devices in TV white space are provided. Methods and apparatus for channel scanning by a device are provided that shorten channel scanning time by using a 5 MHz Measurement Pilot frame at a predetermined location within an enabling device&#39;s channel, regardless of the operating bandwidth of the enabling device. Also provided are methods and apparatus for multi-band dynamic station enablement that locate information regarding an enabling device&#39;s supported regulatory classes and channel numbers within one accessible frame of information and also provide request and response messages to arrange for enablement of a requesting device on a network. Further, methods and apparatus are provided for identifying an interfering device on a network by providing increased information from within a DSE Registered Location element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Application and claims the benefit,under 35 U.S.C. §365 of International Application PCT/US2011/041325filed Jun. 22, 2011 which was published in accordance with PCT Article21(2) on Dec. 29, 2011 in English and which claims the benefit of U.S.Provisional Patent Application No. 61/398,153 filed on Jun. 22, 2010,U.S. Provisional Patent Application No. 61/398,152 filed on Jun. 22,2010 and U.S. Provisional Patent Application No. 61/399,105 filed onJul. 7, 2010

FIELD OF THE INVENTION

The present principles relate to methods and apparatus for networkaccess, enablement, and control of devices in TV white space.

BACKGROUND OF THE INVENTION

Recently, the Federal Communications Commission (FCC) has approved theoperation of unlicensed radio transmitters in the broadcast televisionspectrum at locations where that spectrum is not being used by licensedservices, such as television stations and wireless microphone operators,under certain rules. This unused TV spectrum is often termed “whitespace”. A concept called Cognitive Radio was proposed to implementnegotiated, or opportunistic, spectrum sharing to improve spectrumefficiency for these frequencies.

It can be expected that the implementation of Cognitive Radio (CR) in TVwhite space will be a major topic within wireless communication into thefuture and provide a viable solution to the problem of scarcity of thewireless spectrum. In 2004, based on the expectation of unlicensed useof TV white space, under the charter of an IEEE 802 Standards Committee,a working group named IEEE 802.22 was established to develop a standardfor a Cognitive Radio-based PHY/MAC/air interface for use bylicense-exempt devices on a non-interfering basis in spectrum that hasalready been allocated to the TV Broadcast Service. The IEEE 802.22working group is also called the WRAN Group, since it is essentiallydeveloping an air interface for a Wireless Regional Area Network (WRAN)with a range as large as 30 miles.

An alternate idea is to standardize the use of this spectrum to provideservices similar to that of the traditional IEEE 802.11 WiFi standard.This effort to use TV white space for WiFi access is known as 802.11af.The difference between the traditional 802.11 standards and 802.11 of isthat 802.11 of will be for WiFi operation in the TV white spaces.

TV white space (TVWS) consists of fragments of TV channels. Thus,depending on the usage of TV broadcasting and wireless microphones, thespectrum opportunity may be 6 MHz, 12 MHz, 18 MHz, . . . assuming that aTV channel is 6 MHz wide. In addition, the spectrum opportunity mayhappen in any of the TV bands. Thus, the spectrum opportunity in TVWSdiffers from the traditional 802.11 bands of 2.4 GHz, 3.6 GHz and 5 GHzin that the center frequency and channel bandwidth are variable.

Due to the combinations of bandwidths in TVWS, and variable centerfrequencies, the channel access delay and the complexity in findingavailable bandwidth can be large. In addition, as part of the process tofind available bandwidth, unlicensed 802.11 devices wishing to operateas dependent stations are subject to channel permissioning andregulatory controls. Once transmitting, these unlicensed devices need tobe identifiable to a database administrator in case they causeinterference to other authorized devices.

SUMMARY OF THE INVENTION

The channel access, enablement, and control of stations operating in TVwhite space are addressed by the present principles, which are directedto methods and apparatus for access, enablement and control of devicesin TV white space. Using the principles described herein, access to theTV white space medium is provided with lower channel scan times byutilizing fast passive scanning of a Measurement Pilot Frame of 5 MHzbandwidth, regardless of whether the operating channel bandwidth is 5MHz, 10 MHz, or 20 MHz. Permission to operate over multiple bands isenabled under the present principles by employing multi-band dynamicstation enablement (DSE) and two new information frames. In addition,increased station identification information is provided under thepresent principles to identify interfering devices within a network.

According to one aspect of the present principles, there is provided amethod for channel scanning by a device that shortens the scanning timeby using a 5 MHz Measurement Pilot frame at a predetermined locationwithin an enabling device's channel, regardless of the operatingbandwidth of the enabling device.

According to another aspect of the present principles, there is provideda method for channel scanning by an enabling device within a networkthat transmits a 5 MHz Measurement Pilot frame at a predeterminedlocation within its channel, regardless of its operating bandwidth.

According to another aspect of the present principles, there is provideda method for multi-band dynamic station enablement that transmitsinformation regarding an enabling device's supported regulatory classesand channel numbers within one accessible frame of information and alsoprovides request and response messages to arrange for enablement of arequesting device on a network.

According to another aspect of the present principles, there is provideda method for multi-band dynamic station enablement by an enabling deviceon a network. The method transmits information regarding an enablingdevice's supported regulatory classes and channel numbers within oneaccessible frame of information and also exchanges request and responsemessages to arrange for enablement of a requesting device on a network.

According to another aspect of the present principles, there is provideda method for increased information from within a DSE Registered Locationelement to be used for improved identification of interfering devices ona network.

According to another aspect of the present principles, there is providedan apparatus for channel scanning by a device that shortens the scanningtime by using a 5 MHz Measurement Pilot frame at a predeterminedlocation within an enabling device's channel, regardless of theoperating bandwidth of the enabling device.

According to another aspect of the present principles, there is providedan apparatus for channel scanning by an enabling device within a networkthat transmits a 5 MHz Measurement Pilot frame at a predeterminedlocation within its channel, regardless of its operating bandwidth.

According to another aspect of the present principles, there is providedan apparatus for multi-band dynamic station enablement that transmitsinformation regarding an enabling device's supported regulatory classesand channel numbers within one accessible frame of information and alsoprovides request and response messages to arrange for enablement of arequesting device on a network.

According to another aspect of the present principles, there is providedan apparatus for multi-band dynamic station enablement of a requestingdevice on a network. The apparatus transmits information regarding anenabling device's supported regulatory classes and channel numberswithin one accessible frame of information and also exchanges requestand response messages with a device seeking to become enabled to arrangefor enablement of that requesting device on a network.

According to another aspect of the present principles, there is providedan apparatus for increased information from within a DSE RegisteredLocation element to be used for improved identification of interferingdevices on a network.

These and other aspects, features and advantages of the presentprinciples will become apparent from the following detailed descriptionof exemplary embodiments, which are to be read in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the IEEE 802.11 Medium Access Control (MAC) architecture.

FIG. 2 shows the format of one type of 802.11 Management Frame, theBeacon frame.

FIG. 3 shows a list of the Public Action field values under the presentprinciples.

FIG. 4 a shows the Condensed Capability Information field of a regularMeasurement Pilot frame. FIG. 4 b shows the Condensed CapabilityInformation when using a 5 MHz Measurement Pilot frame under the presentprinciples.

FIG. 5 shows a Slot Time subfield.

FIG. 6 shows the format of the DSE Registered Location element under thepresent principles.

FIG. 7 shows an example of the Regulatory Classes and Channel Numbersfield under the present principles.

FIG. 8 shows a further example of Public Action field values that areused in an 802.11 Management frame under the present principles.

FIG. 9 shows the format of a multi-band DSE request frame under thepresent principles.

FIG. 10 shows the format of the multi-band DSE response frame under thepresent principles.

FIG. 11 shows the format of the Regulatory ID field of the DSERegistered Location element of an 802.11 Management frame.

FIGS. 12 (a) and (b) show embodiments of methods for channel scanningunder the present principles performed by a device seeking access to anetwork, and by a device that can authorize access, respectively.

FIGS. 13 (a) and (b) show embodiments of apparatus for channel scanningunder the present principles for a device seeking access to a network,and by a device that can authorize access, respectively.

FIGS. 14 (a) and (b) show embodiments of methods for multi-band dynamicstation enablement under the present principles performed by a deviceseeking enablement to a network, and by a device that can authorizeenablement on a network, respectively.

FIGS. 15 (a) and (b) show embodiments of apparatus for multi-banddynamic station enablement under the present principles for a deviceseeking enablement to a network, and by a device that can authorizeenablement on a network, respectively.

FIG. 16 shows an embodiment of a method for identifying an interferingTV white space device under the present principles.

FIG. 17 shows an embodiment of an apparatus for identifying aninterfering TV white space device under the present principles.

DETAILED DESCRIPTION

Recently, based on the approval of the FCC, unlicensed radiotransmitters can utilize the broadcast television spectrum at locationswhere that spectrum is not being used by licensed services, according toIEEE Standard for Information Technology-Telecommunications andInformation Exchange Between Systems-Local and Metropolitan AreaNetworks-Specific Requirements—Part 11: Wireless LAN Medium AccessControl (MAC) and Physical Layer (PHY) Specifications,” IEEE, New York,N.Y., June 2007. This unused TV spectrum is often termed “TV whitespace”. The charter of the IEEE 802.22 working group is to develop astandard for a cognitive radio-based PHY/MAC/air interface for use bylicense-exempt devices on a non-interfering basis in spectrum that isallocated to the TV Broadcast Service. Another group, the 802.11 ofgroup, is standardizing the use of TV white spaces for servicestraditionally provided by the 802.11 WLAN standard. The IEEE 802.11 afgroup is significant because there are already a tremendous number of802.11 devices in the market. Under the principles described herein, wedescribe approaches for TV white space devices, also known as TV banddevices (TVBD), acting as dependent stations (STA), to access and gainpermission to operate in the TV white space spectrum, over a number ofdifferent bandwidths, and to be identified should they causeinterference to other devices.

The fundamental access method of the IEEE 802.11 Medium Access Control(MAC) is a Distributed Coordination Function (DCF) known as CarrierSense Multiple Access with Collision Avoidance (CSMA/CA). It is adistributed system while most of other systems such as IEEE 802.16 andIEEE 802.22 are centralized systems. The 802.11 af group uses a DCFaccess function for its MAC layer.

The basic 802.11 MAC layer employs Distributed Coordination Function(DCF) with enhanced distributed channel access (EDCA) mechanism tocompete for wireless medium. FIG. 1 (from IEEE Standard for InformationTechnology-Telecommunications and Information Exchange BetweenSystems-Local and Metropolitan Area Networks-Specific Requirements—Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)Specifications,” IEEE, New York, N.Y., June 2007) illustrates the IEEE802.11 MAC architecture. The basic MAC rule is that DCF and HybridCoordination Function (HCF) are provided through the services of the DCFto support Quality of Service (QoS). The Point Coordination Function(PCF) is a centralized mechanism and it is seldom used. The HCF usesboth a contention-based channel access method, called the EDCA mechanismfor contention-based transfer, and a controlled channel access, referredto as the HCF controlled channel access (HCCA) mechanism, forcontention-free transfer.

The EDCA mechanism provides differentiated, distributed access to thewireless media for stations (STAB) using eight different user priorities(UPs). It defines four access categories (ACs) that provide support forthe delivery of traffic with UPs at the STAB. The four ACs and theircorresponding parameters are listed in Table 1 (from IEEE Standard forInformation Technology-Telecommunications and Information ExchangeBetween Systems-Local and Metropolitan Area Networks-SpecificRequirements—Part 11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) Specifications). In Table 1, TXOP refers totransmission opportunity. It is the time that a station has the right totransmit on the channel, limited by TXOPLimit. An initiation of the TXOPoccurs when a STA obtains access to the medium through DCF. Multipleframes may be transmitted in an acquired TXOP if there is more than oneframe pending in the AC for which the channel has been acquired.However, those frames that are pending in other ACs shall not betransmitted in this TXOP.

Based on the FCC Second Report and Order of November 2008, TV channels2-51 except channels 3, 4 and 37, can be used for radio transmissionsprovided that the incumbent licensed signals, i.e., TV broadcast andwireless microphone (WM) signals, are not interfered. Thus, the spectrumopportunity in TVWS consists of fragments of single or multiple TVchannels (TVCs). The size of the each fragment can vary from 1 TVC toseveral TVCs. It has been shown that even in urban areas, a fragment canhave as many as four contiguous TVCs. In rural areas, fragments of up to16 TVCs are possible. Basically, more channel bandwidth means higherdata rate and smaller data packet sizes. Having a small data frame isimportant for a CSMA system.

The spectrum opportunities in TVWS can be classified into twocategories, which are contiguous and non-contiguous.

In the first case, the available TVCs are contiguous. TV White Spacedevices may employ 5 MHz, 10 MHz, or 20 MHz bandwidths corresponding to1, 2, and 4 contiguous available TV channels. Ideally, the larger thechannel bandwidth, the higher the data rate. From this point of view, asystem should use four contiguous TVCs as often as possible.Practically, this is not always possible if four contiguous channels arenot available. In the second case, the available TVCs arenon-contiguous. When the available TVCs are not contiguous but withinone TVC of each other, we still want to use them together to increasedata rate and have small packet sizes.

When a device wants to communicate with other devices within a network,it needs to become enabled so that it is allowed to transmit and receivewith the permission of the enabling device, even though it may betransferring data with a different device. Under the principlespresented herein, in order to shorten the channel scan time of a deviceattempting to become enabled within a network, a narrowband MeasurementPilot frame is transmitted by an Access Point (AP) within the network.This Measurement Pilot frame is transmitted periodically by the AccessPoint at a smaller interval than a Beacon Interval. Beacon Frames are atype of Management Frame within the 802.11 MAC protocol. An example of aManagement Frame is shown in FIG. 2, where the Category field indicateswhether the frame is a public frame or a radio measurement frame. TheAction Value can take one of several values to indicate the purpose ofthe frame, such as a Beacon frame. Beacon frames are sent periodicallyby Access Points to broadcast the Access Point's presence. The framescontain information pertaining to the Access Point, such as Service SetIdentifier, Timestamp, supported rates for a wireless LAN, and Beaconinterval. Stations continually scan 802.11 channels to pick up Beaconframe signals from Access Points within their range to decide the AccessPoint to which they should associate. They may also monitor the channelfor Measurement Pilot frames to obtain some of the same information asin a Beacon signal, but at a more frequent interval. Once a device isenabled, it is then described as being dependent upon the Access Pointthat enables it, which is called an Enabling AP.

The Measurement Pilot Frames are transmitted by Access Points morefrequently than Beacon frames. The Measurement Pilot Frames are definedin the IEEE 802.11k standard and comprise just some of the informationcontained within a Beacon frame and, for that reason, are smaller insize. They assist stations with fast passive channel scanning. Under thepresent principles, the Measurement Pilot Frames have a fixed channelbandwidth of 5 MHz, in a location that is known a priori to both AccessPoints and devices seeking to become enabled. The Measurement PilotFrames are transmitted in this predetermined 5 MHz portion of thechannel regardless of the operating bandwidth of the AP that transmitsit. This shortens the channel access time compared to Measurement PilotFrames transmitted over a 10 MHz, 20 MHz, or 40 MHz bandwidth. This isbecause with larger operating bandwidths, a Measurement Pilot could belocated at a number of center frequencies. Under the present principles,a station looking to become a dependent STA only needs to search aparticular 5 MHz portion of spectrum regardless of the channel bandwidthto find the Measurement Pilot Frame.

FIG. 3 shows a field from an 802.11 Public Action frame that includes avalue for a 5 MHz Measurement Pilot under the present principles. APublic Action frame is one type of 802.11 Management Frame. FIG. 4 ashows an example format of the Measurement Pilot Frame's CondensedCapability Information Field when a Measurement Pilot frame, as definedin IEEE 802.11k with an unrestricted bandwidth, is used. FIG. 4 b showsthe Measurement Pilot Frame's Condensed Capability Information Fieldwhen a narrowband, or 5 MHz, Measurement Pilot Frame is used under thepresent principles. In this case, the Slot Time subfield consists of twobits carrying slot time information. The corresponding slot times for 5,10, and 20/40 MHz channel spacing (from top to bottom) as defined in theOFDM MAC layer are listed in FIG. 5.

The parameter aSlotTime defines a time interval, a multiple of which atransmitting device waits before transmitting frames of data whenoperating within a network. The parameter aSIFSTime defines a shortinterframe space time, during which a receiver must send an acknowledgesignal back to a transmitter. According to Table 2 (from IEEE Standardfor Information Technology-Telecommunications and Information ExchangeBetween Systems-Local and Metropolitan Area Networks-SpecificRequirements—Part 11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) Specifications), aSlotTime and ASIFSTime aredifferent for different channel bandwidths. Devices can set their ownaSlotTime and aSIFSTime to these values when joining a network dependingon their own operating bandwidths.

802.11 WLAN devices (or stations, STAB) operate in the 2.4 GHz, 5 GHzand US 3650 MHz bands, but can also operate in TVWS as secondary users.The US 3650 MHz band is a licensed band, and because many 802.11 deviceshave multi-band capability, some may operate in both licensed andunlicensed bands. A device may connect with an Access Point in anunlicensed band and then attempt to switch to a licensed band. Any802.11 devices must receive permission and are subject to regulatorycontrol to operate as dependent stations within TVWS or within alicensed band. The 802.11 devices use dependent station enablement (DSE)procedures to periodically receive permission and have permissionrescinded from them by an enabling station. DSE procedures are specifiedin IEEE 802.11y-2008. The enablement signals are not required to be sentwithin the same band that a device is operating. For example, DSE may beperformed in the 2.4 GHz band and the TVWS spectrum may be the operatingband for a dependent 802.11 device. Therefore, under the presentprinciples, the DSE protocol is extended to support multi-bandenablement by allowing the DSE Registered Location element to includeinformation of regulatory class and channel numbers supported by anenabling STA. This allows an enabling STA to give or deny permission toa dependent STA across a number of bands and available channels at once,using the DSE Registered Location element.

FIG. 6 shows a DSE Registered Location element using one embodiment ofthe present principles, which is the addition of fields for Regulatoryclasses and Channel Numbers, along with a field indicating its length.FIG. 7 shows an example of the Regulatory Classes and Channel Numbersfields. In this example, a subfield indicates a particular regulatoryclass, followed by an associated Channel Length subfield, and anassociated Channel Numbers subfield. Each additionally supportedRegulatory Class follows the first Regulatory Class subfields andcontains similar subfields. For each class, the Channel Length subfieldindicates the number of channels which are supported by the enablingSTA. The Channel Numbers subfield lists all of the channel numberssupported by the enabling STA in the Regulatory Class.

Also under the present principles, two Public Action frames are addedfor the multi-band enablement procedure. These two Public Action framesare for Multi-band DSE request and Multi-band DSE response. FIG. 8 showsan example of the values within a field of the 802.11 Public Actionframe previously shown in FIG. 3, but with the addition of valuesindicative of Multi-band DSE request and Multi-band DSE response.

FIGS. 9 and 10 show examples of what is included in the Multi-band DSErequest frame and Multi-band DSE response frame format. Multi-bandenablement is carried out by an enablement requester STA transmitting aMulti-band DSE request frame that comprises the requester STA MACaddress, and supported regulatory classes. Upon receipt of a PublicAction Multi-band DSE Request frame, a responding enabling STA mayenable the requesting STA by transmitting a Multi-band DSE responseframe comprising the requesting STA's MAC address, the enabling STA'sMAC address, the result of the requested enablement, an enablementidentifier and the regulatory class and channel number that the enabledSTA will use.

Once operating, TV white space devices must be identifiable in order toresolve issues of interference with other devices. DSE STAidentification will be used to resolve some interference issues byhaving dependent STAB broadcast the location of the STA that has enabledthem, as well as a unique code. In this way, a victim of theinterference can identify and notify a party responsible for correctingthe interference, but the privacy of the dependent STA's operator ismaintained. The information contained in the DSE Registered Locationelement includes the latitude, longitude, and altitude of the enablingSTA along with a unique code. Under the present principles, the FCC IDand manufacturer's serial number of the device causing interference arealso included within a Regulatory ID subfield in the DSE RegisteredLocation element to further identify the responsible operator. The DSERegistered Location element is one type of Action Frame within the802.11 standard. FIG. 11 illustrates an example of the format of theRegulatory ID subfield, showing the FCC ID and Manufacturer serialnumber fields, along with length fields to indicate their respectivelengths.

An embodiment of a method 1200 for channel scanning is shown in FIG. 12(a). A frame, such as a Public Action frame for example, is received by adevice on a channel in a network and a determination is made in step1210 whether a value in the frame indicates that a narrowband pilotsignal is being sent by an Access Point within the network. If the framevalue indicates the presence of a narrowband pilot signal, in step 1220,the pilot signal is extracted from a predetermined narrowband portion ofthe spectrum. The particular narrowband portion of the spectrum is knowna priori by devices, for example, according to a standard. If the framevalue indicates that a narrowband pilot signal is not present, themethod returns to waiting to receive another Public Action frame. Instep 1230, information within the pilot signal, such as utilization orpower level, of the Access Point, for example, is used to make adetermination whether to send a request for enablement to the devicesending the pilot signal. This determination is made by the deviceseeking enablement based on, for example, whether its throughput will besufficient given the utilization level information of the Access Point,as received in the pilot signal, or an indication in the pilot signalthat will lead a device seeking enablement to either request enablementon the first Access Point or seek another Access Point for enablement inorder to maximize the throughput of all traffic on the network.

FIG. 12 (b) shows an embodiment of a method 1240 for channel scanningwhich occurs at the device sending the pilot signal, such as an AccessPoint. The narrowband pilot is transmitted in step 1250. The AccessPoint then waits for an enablement request in step 1260. After receivingthe enablement request, in step 1270, the Access Point determineswhether authorization should be given to the device seeking enablementon the network. In step 1280, the Access Point can authorize the deviceseeking enablement for access to the network.

An embodiment of an apparatus 1300 for channel scanning is shown in FIG.13( a). The apparatus is comprised of a comparator 1310, whichdetermines if a value in a received frame indicates the presence of anarrowband pilot signal. If so, extractor 1320, whose input is in signalcommunication with the output of comparator 1310, finds the pilot signalwithin a predetermined narrowband portion of the channel spectrum,regardless of the operating bandwidth of the device sending the pilotsignal. The output of extractor 1320 is in signal communication with theinput of decision circuit 1330. Decision circuit 1330 determines whethera request for enablement should be sent to the device sending the pilotsignal, based on information, such as utilization levels or power levelsof the Access Point, extracted from the pilot signal by extractor 1320.

FIG. 13( b) shows an embodiment of an apparatus 1350 for channelscanning. Transmitter 1360 sends a narrowband pilot signal to devicestrying to gain access to a network. Circuitry 1370 waits for a requestfrom a device seeking enablement on the network. The output of circuitry1370 is in signal communication with the input of decision circuit 1380,that determines whether authorization for enablement on the networkshould be given to the device seeking enablement. Since an Access Pointuses 802.11 DSE procedures to periodically grant and rescind permissionto dependent devices on the network, the determination made by decisioncircuit 1380 is based on whether the enabling device has sufficientresources to maintain control and permissioning to the device seekingenablement. The output of decision circuit 1380 is in signalcommunication with the input of access circuit 1390 that can authorizethe device for access to the network.

An embodiment of a method 1400 for multi-band dynamic station enablementby a device seeking to become enabled on a network under the presentprinciples is shown in FIG. 14 a. The method begins in step 1410 byreceiving a data element, such as an 802.11 Management frame containingchannel information supported by a potential enabling device. Next, anenablement request is sent by the device seeking enablement in step 1420using the received channel information from step 1410. In response, anenablement response is received in step 1430 from a device, such as anAccess Point, that can authorize enablement on a network.

An embodiment of a method 1450 for multi-band dynamic station enablementby an enabling device, such as an Access Point, under the presentprinciples is shown in FIG. 14 b. The method begins in step 1460 when adata element is sent by the enabling device to any devices seeking tobecome enabled on the network. The data element comprises channelinformation that is supported by the enabling device. Based on thisinformation within the data element, a device seeking to become enabledmay send an enablement request, and in step 1470, the enabling devicereceives this enablement request. If the enabling device determines,based on information, for example, on its utilization levels andresources available, it can send an enablement response to the devicesseeking to become enabled, in step 1480.

An embodiment of an apparatus 1500 for multi-band dynamic stationenablement by a device seeking to become enabled in a network under thepresent principles is shown in FIG. 15 a. The apparatus comprises afirst receiver 1510 for receiving a data element over a network thatcomprises channel information supported by a device, such as an AccessPoint, for example, that can enable other network devices. The output ofreceiver 1510 is in signal communication with transmitter 1520 thatsends an enablement request to another station on the network to requestenablement. A second receiver 1530 receives an enablement response froma requested device, such as the Access Point, on the network indicatingwhether enablement has been allowed.

An embodiment of an apparatus 1550 for multi-band dynamic stationenablement by an enabling device in a network under the presentprinciples is shown in FIG. 15 b. The apparatus comprises a firsttransmitter 1560 for sending a data element capable of being received bya device seeking to become enabled on the network, comprising channelinformation supported by the enabling device. The output of firsttransmitter 1560 is in signal communication with a receiver 1570 thatreceives an enablement request from a device seeking to become enabledif that device determines that the channel information sent from theenabling device matches its needs. A second transmitter 1580 sends anenablement response to the device seeking to become enabled indicatingwhether enablement has been allowed on the network.

An embodiment of a method 1600 for identifying a dependent TV whitespace device causing interference in a network is shown in FIG. 16. Themethod begins by receiving a frame of information, such as the DSERegistered Location Announcement containing a DSE Registered Locationelement, for example, in step 1610. From this frame of information,values can be determined, in step 1620, that indicate the FCC ID andmanufacturer's serial number of a device that may be causinginterference. When a third-party licensed device is being interfered, itneeds a way to determine what device is causing the interference. Theinformation transmitted within the DSE Registered Location element isused to track the interfering device. If the interfering device does notstop transmissions, its enabling Access Point is required to rescindpermission to operate within the network.

An embodiment of an apparatus 1700 for identifying a dependent TV whitespace device causing interference in a network is shown in FIG. 17. Areceiver 1710 is used to retrieve a frame of information, such as a DSERegistered Location element, for example, that contains informationindicative of the FCC ID and Manufacturer serial number of a device thatis causing interference in a network. The output of receiver 1710 is insignal communication with the input of processor 1720 that uses the FCCID and Manufacturer serial number to identify the interfering device.

One or more embodiments have been described for channel scanning by adevice in TV white space. The embodiments provide efficient passivechannel scanning by searching a predetermined 5 MHz portion of achannel's spectrum for a Measurement Pilot frame signal, which is sentmore frequently than a Beacon signal. The predetermined 5 MHz portion ofspectrum is known a priori to Access Points and devices seekingenablement on a network.

Also provided under the present principles are various embodiments formulti-band dynamic station enablement in a network. These embodimentsallow the regulatory classes and channel numbers that are supported byan enabling device to be found within a DSE Registered Location element,and provide multi-band DSE request and multi-band DSE response messagesto be exchanged. A further embodiment allows the channels where theresponse and request messages are exchanged to be different than thechannel where enabled operation will occur.

Further, under the present principles, one or more embodiments have beenprovided for identifying an interfering dependent TV white space device.Information included in a frame of information, such as, for example,the DSE Registered Location element, is used to identify the FCC ID andmanufacturer's serial number of an interfering device.

We thus provide one or more implementations having particular featuresand aspects. However, features and aspects of described implementationsmay also be adapted for other implementations. For example, theseimplementations and features may be used in the context of otherwireless networks or systems. The implementations and features need notbe used in a standard.

Reference in the specification to “one embodiment” or “an embodiment” or“one implementation” or “an implementation” of the present principles,as well as other variations thereof, mean that a particular feature,structure, characteristic, and so forth described in connection with theembodiment is included in at least one embodiment of the presentprinciples. Thus, the appearances of the phrase “in one embodiment” or“in an embodiment” or “in one implementation” or “in an implementation”,as well any other variations, appearing in various places throughout thespecification are not necessarily all referring to the same embodiment.

The implementations described herein may be implemented in, for example,a method or a process, an apparatus, a software program, a data stream,or a signal. Even if only discussed in the context of a single form ofimplementation (for example, discussed only as a method), theimplementation of features discussed may also be implemented in otherforms (for example, an apparatus or program). An apparatus may beimplemented in, for example, appropriate hardware, software, andfirmware. The methods may be implemented in, for example, an apparatussuch as, for example, a processor, which refers to processing devices ingeneral, including, for example, a computer, a microprocessor, anintegrated circuit, or a programmable logic device. Processors alsoinclude communication devices, such as, for example, computers, cellphones, portable/personal digital assistants (“PDAs”), and other devicesthat facilitate communication of information between end-users.

Implementations of the various processes and features described hereinmay be embodied in a variety of different equipment or applications.Examples of such equipment include a web server, a laptop, a personalcomputer, a cell phone, a PDA, and other communication devices. Asshould be clear, the equipment may be mobile and even installed in amobile vehicle.

Additionally, the methods may be implemented by instructions beingperformed by a processor, and such instructions (and/or data valuesproduced by an implementation) may be stored on a processor-readablemedium such as, for example, an integrated circuit, a software carrieror other storage device such as, for example, a hard disk, a compactdiskette, a random access memory (“RAM”), or a read-only memory (“ROM”).The instructions may form an application program tangibly embodied on aprocessor-readable medium. Instructions may be, for example, inhardware, firmware, software, or a combination. Instructions may befound in, for example, an operating system, a separate application, or acombination of the two. A processor may be characterized, therefore, as,for example, both a device configured to carry out a process and adevice that includes a processor-readable medium (such as a storagedevice) having instructions for carrying out a process. Further, aprocessor-readable medium may store, in addition to or in lieu ofinstructions, data values produced by an implementation.

As will be evident to one of skill in the art, implementations may useall or part of the approaches described herein. The implementations mayinclude, for example, instructions for performing a method, or dataproduced by one of the described embodiments.

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made. For example,elements of different implementations may be combined, supplemented,modified, or removed to produce other implementations. Additionally, oneof ordinary skill will understand that other structures and processesmay be substituted for those disclosed and the resulting implementationswill perform at least substantially the same function(s), in at leastsubstantially the same way(s), to achieve at least substantially thesame result(s) as the implementations disclosed. Accordingly, these andother implementations are contemplated by this disclosure and are withinthe scope of this disclosure.

The invention claimed is:
 1. A method for channel scanning by a deviceseeking enablement within a wireless network, comprising: determiningwhether a broadcast information signal received by the device isindicative of a narrowband pilot signal being sent from an enablingdevice in the network; extracting said narrowband pilot signal, from apredetermined portion of spectrum, in response to the broadcastinformation signal indication; using information from the narrowbandpilot signal to determine whether to send to the enabling device arequest for enablement of the device on the network.
 2. The method ofclaim 1, wherein the device operates in TV white space.
 3. The method ofclaim 1, wherein the broadcast information signal is an IEEE 802.11public action frame.
 4. The method of claim 1, wherein the narrowbandpilot signal is contained within a 5 MHz spectrum.
 5. The method ofclaim 1, wherein said information from the narrowband pilot signalcomprises utilization level of an access point.
 6. The method of claim1, wherein said determination whether to seek to become enabled on thenetwork is made to optimize network throughput.
 7. An apparatus forchannel scanning by a device seeking enablement within a wirelessnetwork, comprising: a comparator for determining whether a broadcastinformation signal received by the device is indicative of a narrowbandpilot signal being sent from an enabling device in the network; anextractor for extracting said narrowband pilot signal from apredetermined portion of spectrum in response to the broadcastinformation signal indication; a decision circuit for using informationfrom the narrowband pilot signal to determine whether to send to theenabling device a request for enablement of the device on the network.8. The apparatus of claim 7, wherein the device operates in TV whitespace.
 9. The apparatus of claim 7, wherein the broadcast informationsignal is an IEEE 802.11 public action frame.
 10. The apparatus of claim7, wherein the narrowband pilot signal is contained within a 5 MHzspectrum.
 11. The apparatus of claim 7, wherein said information fromthe narrowband pilot signal comprises utilization of an access point.12. The apparatus of claim 7, wherein said determination whether to seekto become enabled on the network is made to optimize network throughput.